l. Field of the Invention
This invention relates to a battery filler for filling a number of electric storage battery cells with acid, or topping them up with distilled water from a reservoir, for example, for use with an assembly of electric storage batteries mounted in a vehicle for propulsion of the vehicle.
2. Summary of the Invention
An object of the present invention is to provide a battery filler which is simple and safe to use.
According to the invention, a battery filler includes a reservoir, a conduit assembly for leading fluid from the reservoir to one or more cells having filling devices which prevent further liquid entering the cell when a certain level has been reached, and a pump coupled to the conduit means downstream of the batteries for drawing fluid by vacuum or suction from the reservoir to the cells.
The pump reduces the pressure in the conduit assembly, and so tends to prevent any loss of acid from the cells through any slight leaks in the conduits.
Preferably there is a sump in the conduit assembly between the cells and the pump, in which liquid drawn through the conduit assembly by siphon, once the cells have all been filled. The liquid can be collected after being from the sump can eventually be returned to the reservoir by opening a drain valve in a connection from the sump to the reservoir.
Preferably there is a level responsive switch in the sump arranged to initiate emptying of the conduit assembly. Thus, when the level in the sump rises to the level of the switch, it will be known that the cells are all full. However, there will still be liquid in the conduit means, and so operation of the pump can continue, for example, for a predetermined interval set on a timer during which time air at atmospheric pressure may be introduced to the conduit assembly at the reservoir end in order to displace the excess liquid and drive it into the sump under the suction provided by the pump. After the conduit assembly has been evacuated, the pump can then be switched off, and the drain valve opened, and then it can be arranged that a lamp or other indicator shows that the conduit assembly can be disconnected from the battery.
The conduit assembly can be arranged to be connected to the battery by simple connections, so that after they have been connected, and the equipment has been switched on, it can be left until the indicator shows that filling has been completed, and then the conduits can be simply disconnected.
The reservoir, sump, pump and conduit means are all conveniently mounted on a trolley for easy movement from one set of batteries to be filled to another.
The emptied liquid can be returned to the reservoir by way of a large pipe having an explosion minimising vent, so that gas can escape safely if the unit is inadvertently left connected during charging.